The present invention relates to improved methods and apparatus for managing fiber optic connections and fiber optic cables as part of a fiber optic communication system. More particularly, the present invention relates to a system for managing and containing slack fiber optic cable, especially in a high connection-density application such as a telecommunications operations center, wherein numerous in-coming and out-going fiber optic cables meet at a central access point.
Within recent years, there has been a rapidly increasing development and use of telecommunications in business and personal activities. Simultaneously, there has been an accelerating trend toward xe2x80x9cconvergencexe2x80x9d in the telecommunications industry. That is, many historically distinct forms of telecommunications, e.g., telephone, data transmission, e-mail, radio, television, videoconference, internet access, and on-line applications, are being combined into a single channel of communication. This combination of factors is causing a paradigm shift in the amount of bandwidth necessary for telecommunications service to modem office buildings. The increased bandwidth requirements cannot be effectively satisfied by traditional copper cables, but, instead, requires switching to fiber optic cable.
Although much attention has been paid to the electrical and electronic techniques for using the bandwidth in fiber optic cable and for interconnecting the signals of copper cable and fiber optic cable, relatively less attention has been given to the unique physical needs of handling, connecting, and maintaining fiber optic cable. However, the mechanical devices that have been developed for handling copper cable do not work well for fiber optic cable because of the relatively delicate, yet technically precise nature of fiber optic cable.
For example, unlike copper cable, fiber optic cable cannot be readily cut and spliced on demand to make a desirable connection fit in the field. Rather, fiber optic cable is purchased in predetermined lengths, with connectors that have been installed in the factory. Field workers must utilize these predetermined lengths of cable, regardless of whether the length is appropriate for the task at hand. When both ends of a fiber optic cable are connected to equipment at two separate points, a certain amount of slack cable is created, as the necessary result of the use of predetermined lengths of cable. Such slack cable ideally should be contained within a limited amount of space, preferably as close to the termination points as possible. At the same time, the relatively fragile and delicate nature of fiber optic cable prohibits bundling excess cable as might be done with copper cable. If fiber optic cable is excessively bent or stressed, the signal within may become seriously disrupted.
Moreover, it must be recognized that an operations center, such as occurs in the field of this invention, typically houses hundreds (and sometimes thousands) of fiber optic cables. It is particularly important that such an operations center provide for installing the fiber optic cables in a manner that secures and protects any excess fiber optic cable without compromising its relatively delicate nature. Yet, in the event that equipment is changed or moved, each individual fiber optic cable must also be maintained in such a manner that it can be identified, isolated, and retrieved without unduly disturbing other fiber optic cables.
These considerations are made all the more acute by the need to increase the number of connections that may be accommodated in a given area. As the connection density increases, the resulting cable congestion becomes a problem, as more and more cables are routed across the system. Therefore, there is a need in the industry for a cable management system that is capable of accommodating the large number of cables necessary to support high connection-density equipment.
It should also be recognized that a fiber optic cable may be connected to a variety of different type devices which are also housed in the operations center, i.e., patch panels of different sizes, splice drawers, connector modules, etc. There is a need within the industry for a fiber optic cable management system that may facilitate the substitution and replacement of one such device by another, without the need to remove or reinstall all of the fiber optic cable associated with the original device. Furthermore, when it is necessary to upgrade or repair equipment, maintaining system operation during these procedures is an important consideration. Consequently, there is need in the prior art for a cable management system organized in a manner that allows for system operation during upgrading or maintenance.
The foregoing problems are made even more difficult because the operations center actually typically comprises a three-dimensional array of devices and fiber optic cables. That is, the operations center typically houses many columns and rows of such racks, with each rack containing a vertical array of devices attached to hundreds and possibly thousands of such fiber optic cables. Each such cable must be identifiable, retrievable, and replaceable, without disrupting the surrounding cables.
Finally, it must be recognized that all of the foregoing problems exist in a commercial environment without a single established standard for size. Historically, products within the xe2x80x9cpublic networkxe2x80x9d were designed by ATandT and Western Electric, and utilized racks that were 23 inches wide, holding devices and enclosures that were 19 inches wide. The xe2x80x9cpublic networkxe2x80x9d was then connected at some point to the premises in a particular building. Products intended for a xe2x80x9cpremises networkxe2x80x9d were historically based upon racks that were 19 inches wide, holding devices and enclosures that were 17 inches wide. The Telecommunications Act of 1996 has opened and triggered widespread competition within the telecommunications market. However, it has done so without establishing standards vis-xc3xa1-vis the mechanical aspects of an operations center. Different companies are adopting different physical standards, and the line of demarcation between xe2x80x9cpublic networkxe2x80x9d and xe2x80x9cpremises networkxe2x80x9d products is becoming fragmented and blurred. As a result, there is a particular need for products that can solve the foregoing problems in the context of both public network and premises network environments.
The above discussed and other drawbacks and deficiencies of the prior art are overcome or alleviated by the high density slack cable management system of the present invention. In accordance with the present invention, the slack cable management system comprises a panel that is secured to a telecommunications network rack, preferably between adjacent network racks, the panel having a plurality of spools secured along the length of the panel to receive slack cable. The spools have an elongate, substantially half-cylindrical shaft and an end flange, the shaft having an upper curved cable-contacting surface to provide bend radius control to cable passing over the spool. The substantially half-cylindrical design of the spools allows the spools to be placed much closer together than is possible with cylindrical spools, without impairing the ability of a field technician to access the spools, and without reducing the amount of slack cable that may be looped over a given spool. A main spool having a fully-cylindrical shaft may be included to provide bend radius control to cable passing over or under the main spool. The spools may be removably secured to the rack or panel.
By enabling the spools to be placed closer together along the panel or rack compared to cylindrical spools, greater flexibility is achieved, in that the field technician may efficiently store slack cable on the system without stretching the cable or creating excessive slack. Additionally, the high spool density allows the system to accommodate slack cable generated by a higher number of connections, allowing for increased connection density. These and other features and advantages of the invention will be apparent to those skilled in the art upon review of the following detailed description of preferred embodiments and drawings.